The correct answer is: B. Kalol, Kandla
IFFCO has two fertilizer factories in Gujarat, one at Kalol and the other at Kandla. The Kalol fertilizer factory is the largest single-location fertilizer plant in the world. It produces urea, ammonia, and ammonium nitrate. The Kandla fertilizer factory produces urea and ammonium nitrate.
The other options are incorrect because they do not list two fertilizer factories that are located in Gujarat. Option A lists Vadodara and Jamnagar, but there is no fertilizer factory in Vadodara. Option C lists Junagadh and Bhavnagar, but there is no fertilizer factory in Junagadh. Option D lists Mundra and Valsad, but there is no fertilizer factory in Valsad.